My auxillary fan on my 97e300d has stopped working. I have tried pressing the auto buttons on the a/c unit, still no fan. I checked the fuses in the box on the drivers side. I did not see anything labled aux. fan, but fuses were OK anyway. I have read on other posts about a resistor. The fan spins freely. I have not tried to jump the fan from the battery, not sure how to do that.
On hot days engine goes above 100c when in traffic and idling. It use to never move above 80c.
I know this has been discussed before, I could not find anything on a 97 e300d. Sorry for any duplication. I appreciate any and all help.

There isn't a resistor. You have one of a possible three fan control modules. If you fan turns with power applied, you'll have to find out which circuit you have and go from there.

The fan power terminals are right next to the high-side service port, at the upper left front side of the condenser.

Also see the other thread on this page on the 210 auxiliary fan.

I do not understand what you mean by high-side port, but I did press both AUTO buttons and the fan did not run.
I then pressed the REST button, then went to #20 and it said 0. Does this mean the fan is bad or do I need to check something else.
Thanks for the help.

With ignition off, check to see of the fan with the motor (driver's side of the pair) spins freely with no bearing noise whatsoever. You can get just the motorized one and replace. I imagine they have it at FastLane parts in this site. I had to replace mine as it would barely turn by hand and it was obvious that the bearings were shot, so I got a replacement unit from the local dealer since they had it in stock and I wanted to do it that day.

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Byron Herrington
'96 E300D 162,000 miles
'97 Toyota Land Cruiser
'92 400E (sold)

To jump the fan from the battery, just stick a pair of alligator clips (Radio Shack sells these, you will need 4) on each end of a piece of regular electrical cord (4 clips in all), then unplug the fan (access will probably involve getting under the car), grab each pin with a clip on one end, and attach the two clips on the other end to the + and - battery terminals. It will blow air in either direction, depending on which terminal you clip it to, if it is working.

If it's not working, you could lube it a bit. WD-40 will probably work temporarily, but real grease is what it would need for a permanent fix, I suspect.

If an electric motor doesn't run, the most likely reasons are the bearings, the brushes or the wiring.

Mine wasn't running because what should have been a ceramic fuse holder was actually made of plastic, and had melted to where the intact metal strip wasn't making contact. A veteran mechanic spotted this. A test lite worked, because I was testing the fuse's metal strip.

I have been told that there is a resistor, but it is very well hidden and totally functional on my 85 300TD, if indeed it exists at all.

Good luck!

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Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)

I tried a jumper today with no success. Fan spins freely with no problem.
We put a voltmeter on the fan with no resistance. We put a voltmeteron the lead to the fan, but could get no reading. My helper thinks it might be the sensor and/or thefan.
Does it sound like we checked everything?
My next step is a fan and sensor. Can the sensor be installed without losing refrigerant?
Neighbor put refrigerant lines on the air and readings were really high.
So fan must do a lot of cooling at idle.
Thanks for all the suggestions.

I tried a jumper today with no success. Fan spins freely with no problem.
=============================================
Do you mean the fan works, i.e. blows air, or do you mean that the fan just sits there, but the blades will spin if you turn then by hand?

If the fan works, then the problem is elsewhere. Check the fuse that corresponds to the fan before checking anything else.

Good luck.


Mercedes made a whole bunch of cars. Most of us have experience with one or two models. If you put the year and model of your car in the signature, and perhaps the mileage, it will be easier for those who have the same car you have to answer your questions better.

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Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)

If #20 says 0, you did not hold the AUTO buttons long enough.

If the climate-control module shows the correct information for engine temperature (#6), refrigerant pressure and refrigerant temperature (#7 and 8), the sensors are fine.

If the fan does not turn when you apply power to the terminals, you need one for sure. You'll know if you need a module once you get a good fan motor in there.

Do NOT buy an aftermarket fan assembly. Only replace this with the factory parts. You can replace the left-side motor without replacing the frame, and it will cost you less than buying a piece-of-junk assembly on eBay. Phil (Buy Parts link, above) has the motor. Be sure to also get a new belt.

What are you guys saying, or what is the meaning of, "and I went to #20 and it said 0"

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1998 E300Turbodiesel
1980 300d

Ready- Ronnie

[quote=Richard Eldridge;1576709]I tried a jumper today with no success. Fan spins freely with no problem.
=============================================
Do you mean the fan works, i.e. blows air, or do you mean that the fan just sits there, but the blades will spin if you turn then by hand?

If the fan works, then the problem is elsewhere. Check the fuse that corresponds to the fan before checking anything else.


Sorry, I mean't the fan would spin freely when I spin it by hand.
Fan does not work at all.
97 E300d.
Thanks

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97 E300D (221,000) deceased
08 E320 Bluetec(142000)new for me

If I press the rest button on the acc unit, it brings up a set of values connected to different parts of the system.
I am still learning these.

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97 E300D (221,000) deceased
08 E320 Bluetec(142000)new for me

What do you mean MODULE?

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97 E300D (221,000) deceased
08 E320 Bluetec(142000)new for me

Finally got the time to put in the new fan. I thought a 96 degree day would be perfect to work on it, not really.
Anyway it runs perfectly. I believe it was one of the easiest jobs I have done.
Thanks for all the help.You guys are great.

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97 E300D (221,000) deceased
08 E320 Bluetec(142000)new for me

hello can u share some instructions on how to do this job, thanks changing the aux fan.